I posted on a quit smoking board when I quit 3 1/2 years ago and they had some helpful terms. The first week is Hell week. It sucks. The first three days are the absolute worst! The one good thing about the first week is that you have lots of drive to suceed.
The second week is heck week. Not quite as bad as hell week, but it still sucks donkey balls.
The third week is weak week. This is the week where the cravings calm down just enough for you to start trying to convince yourself that "just one" wont hurt. You also generaly start to get real sick and tired of fighting the cravings and just want some relief all ready!
I can tell you one thing though. The only way to make the cravings go away for good, and to take control of it, is to never ever buy the "just one" theory. I have not had a smoke for over 3 years and it feels good. It was the hardest thing I ever did to quit, but it is so extremely worth it! If nothing else just remember that you want to be around for your grandkids and your great grandkids. My mom was just diagnoised with a serious respitory condition and may only have another two years left thanks to smoking. Avoiding putting your family through what we are going through now with mom is worth it by itself.
Ok, hoping off high horse. Hope it helps someone though.